Study Questions:

Are clinical outcomes affected by the type of treatment strategy used in patients with atrial fibrillation (AF)?

Methods:

This was a retrospective comparison of rhythm-control (n = 2,858) versus rate-control (n = 4,130) strategies among 6,988 patients (median age 74 years) entered into an AF registry. The median follow-up was 2.3 years. The several study outcomes included death, stroke, and heart failure.

Results:

In an analysis adjusted for multiple potential confounding variables, there was a higher risk of first cardiovascular hospitalization in the rhythm-control group (hazard ratio 1.24). There were no significant differences between the two treatment strategies in all-cause death, cardiovascular death, stroke, new-onset heart failure, or major bleeding.

Conclusions:

The authors concluded that a rhythm-control strategy does not improve clinical outcomes compared to a rate-control strategy in patients with AF.

Perspective:

This study has two major limitations: 1) it was a voluntary, observational study without a standardized approach to drug or ablation therapy; and 2) no data are provided on how many patients in the rhythm-control group no longer had episodes of AF. Only 8.6% of patients in the rhythm-control group underwent catheter ablation of the AF, and most received pharmacologic therapy. Given the modest efficacy of antiarrhythmic drug therapy, it is likely that many patients in the rhythm-control group still had episodes of AF. Therefore, while the study can validly conclude that a rhythm-control strategy does not improve outcomes (as already has been demonstrated in several randomized clinical trials), the results cannot be used as evidence that maintenance of sinus rhythm does not improve outcomes compared to AF.